DEA agents visiting Colombia had sex parties funded by narco gangs.

I don't see any reason DEA agents should not participate in sex parties, but if they get anything from drug traffickers, it's a form of corruption. Those agents must be booted out.

However, this incident is part of a general pattern. Prohibition of drugs makes trafficking profitable, and that money is used to corrupt officials at all levels. Even for drugs that are really dangerous, drugs that are foolish to use, prohibition is a bad response.